310 THE COMING OF MAN 



learned. You would not understand it all — none 

 but the great thinkers themselves can do that — 

 but even a part of what they have discovered is a 

 wonderful story. 



This, then, is the story of the sun. 



It is an immense ball of glowing Ught, so large that 

 we cannot picture to ourselves its size, and so far 

 away that we can hardly imagine its distance, for 

 there is nothing upon the earth with which to com- 

 pare it. It may help us to get an idea of its distance 

 to think how long it would take one of our fastest 

 express trains to get there — those trains that take 

 away your breath when they dash by you. 



It would take — now put on your thinking caps — 

 it would take about one hundred and seventy-eight 

 years for that express train to get to the sun, going 

 straight on and never stopping an instant. That is 

 twice as long as a very old man lives. That same 

 train, traveling at the same rate of speed, could go 

 around the equator of the earth, which is its largest 

 part, in seventeen days. 



Just think of it ! To be only seventeen days going 

 around our great world, but one hundred and seventy- 

 eight years on a journey to the sun! 



Can you think how far that would be? Or, can 

 you think how much larger the sun is than our world, 

 when you hear that this sixty-mile-an-hour express 

 train would require five years to go around the sun? ^ 

 There is a great difference between seventeen days 

 and five years. Why, 3^ou are only about twice 

 five years old, and it is a long time since you were a 



1 Figures given by Dolmage. 



